Now, your temptation is to keep the first answer because you know energy is not going to be negative.

你肯定想保留正根,因为你知道能量不会是负值

耶鲁公开课 - 基础物理课程节选

system is the opposite of the open system, no mass and no energy can flow through the boundary.

孤立系与开系正相反，没有质量或能量,能流过它的边界。

麻省理工公开课 - 热力学与动力学课程节选

Here is a chart that just shows the positive energies, and you can see the various components, and then the negative energies and the net.

这是展示正能量的表格，你可以看到不同的成分，负能量和总能量。

麻省理工公开课 - 固态化学导论课程节选

So you don't want to put in a negative energy, that's not going to help you out, you need to put in positive energy to get an electron out of the system. So that's why you'll find binding energies are always negative, and ionization energies are always going to be positive, or you could look at the equation and see it from there as well.

因为这对电离没有帮助,你需要一个正的能量,使得电子脱离这个系统,这就是为什么你会发现,结合能总是负的而电离能总是正的,或者你们看这个方程也可以发现这一点。

麻省理工公开课 - 化学原理课程节选

I have three out of the five energies, and they are all positive.

这有3/5的能量，他们都是正的。

麻省理工公开课 - 固态化学导论课程节选

So let's think about the energy required now to remove a 2 s electron, let's say we're removing it from boron plus 1 versus neutral boron.

那么让我们来想一想,拿走一个，2，s，电子所消耗的能量，假设一个是从正一价硼离子中拿走1,另一个是从中性硼原子中拿走。

麻省理工公开课 - 化学原理课程节选